1. Field of the Invention
The present invention relates to a cleaning apparatus of a semiconductor substrate and a method of manufacturing a semiconductor device which are suitable for manufacturing a semiconductor device using a large diameter substrate.
2. Description of the Related Art
Recently, as a semiconductor device is more highly integrated, a gate width of the semiconductor device has been narrower, while maintaining the height of a gate electrode. As a result, the aspect ratio of the gate electrode has been larger. Moreover, a gap of metal wirings has also been narrower. Further, in order to reduce a capacitance between the wirings, a low dielectric constant film is often used as an interlayer insulating film. Moreover, in order to suppress wiring resistance to a low value, a copper wiring is employed, and the semiconductor device is designed to have a higher height by an amount corresponding to the width decrease. Thus the aspect ratio of the copper wiring has also been larger.
When the copper wiring is formed, a damascene method is employed. In the damascene method, after formed wiring grooves by using a dry etching process in an interlayer insulating film such as a low dielectric constant film, the copper wiring is buried in the wiring grooves. In addition, after the dry etching process is finished, in order to remove adhered matters such as copper oxide, fluorine compound, organic polymer, and inorganic polymer, a wet post-treatment is implemented as cleaning. In the cleaning, an ammonium fluoride-based liquid chemical, or an ammonium phosphate-based liquid chemical is used. The above-mentioned liquid chemicals are preferable for working environment and for safety, because they do not contain deleterious and poisonous substances, thereby, do not belong to dangerous articles. Moreover, since their organic contents are relatively small, the treatment of their waste liquids is also easy.
Moreover, recently, in order to improve yields, enlargement of the diameter of a semiconductor substrate (wafer) has been advanced. Accordingly, although in cleaning (wet post-treatment) of a semiconductor substrate with a diameter of about 8 inch, a batch-type post-treating apparatus is used, in cleaning of a large diameter semiconductor substrate, a single-wafer-type post-treating apparatus has been used. FIG. 12 is a schematic view showing a conventional single-wafer-type post-treating apparatus. In the conventional single-wafer-type post-treating apparatus, a stage 106 on which a substrate 109 is placed is arranged in a treating bath 105. Moreover, a tank 104 storing a liquid chemical, a pump 103 sucking the liquid chemical from the tank 104, a heater 102 heating the liquid chemical sucked by the pump 103, and a nozzle 101 for the liquid chemical spraying the liquid chemical warmed by the heater 102 to the substrate 109 are also provided. Further, nozzle for water cleaning and the like (not shown) are also provided.
The cleaning using such a single-wafer-type post-treating apparatus, suppresses the increase of the contact resistance of the semiconductor device.
However, with increasing the diameter of the semiconductor substrate and the like, defective products tend to occur.
Related arts are disclosed in Patent document 1 (Japanese Patent Application Laid-open No. 2004-337858), Patent document 2 (Japanese Patent Application Laid-open No. 2001-232250), and Patent document 3 (Japanese Patent Application Laid-open No. Hei 11-74179).